J. Lauterbach et al., A FTIRAS STUDY OF CO ADSORBED AT NI(100) SURFACES, Berichte der Bunsengesellschaft fur Physikalische Chemie, 97(3), 1993, pp. 326-328
Citations number
8
Categorie Soggetti
Chemistry Physical
Journal title
Berichte der Bunsengesellschaft fur Physikalische Chemie
Adsorption of CO at Ni(100) surfaces has been studied with Fourier-Tra
nsform Infrared Absorption-Reflection (FTIRA) spectroscopy in the temp
erature range 121 K to 350 K. Up to a coverage of THETA = 0.5 top site
and bridge site bonded CO has been identified by absorption peaks in
the frequency range 2016 to 2048 cm-1 and 1885 to 1949 cm-1, respectiv
ely. The site population is temperature dependent, top sites are prefe
rred at high temperatures, bridge sites at low temperatures. Towards t
he saturation coverage, THETA almost-equal-to 0.67 the top site peak i
s replaced by a broad absorption structure between 2000 and 2100 cm-1,
which contains at least 3 separate peaks. The bridge site related abs
orption remains a single peak but shifts upwards by 20 cm-1 to 1968 cm
-1. This suggests that above a coverage of THETA = 0.5 CO molecules ar
e arranged in an incommensurate adsorption structure, in which a uniqu
e top adsorption site does no longer exist.